It's the federal Endangered Species Act's 40th birthday, and as the landmark legislation reaches middle age it's time for an update.

Think back to 1973, when Richard Nixon signed it into law. Has anything changed since then? Has science progressed? Have politics changed? Has the environmental movement changed?

During the four decades of its existence, the ESA has had its failures -- and its successes. Unfortunately, the failures have far outnumbered the successes. Of the 1,440 species listed under the ESA in the U.S. only a handful have recovered.

The bald eagle was re-established in parts of the Lower 48 states by transplanting the birds from Southeast Alaska, where thousands of them live. Its numbers had been reduced by the loss of habitat, hunting and the use of DDT, a pesticide that caused the shells of its eggs to be too thin.

Once steps were taken to ban DDT and re-establish the bald eagle, the species was back. Today, it is fairly common to see bald eagles in many parts of the Lower 48.

It is a story of how the ESA should work. Identify the problem, the causes and the solutions and move forward.

Unfortunately, it's not that easy in all cases, and the ESA is a part of the reason. Here are some flaws in the ESA:

* The ESA gives just as much importance to lichen, ferns, bugs, fish and snails as it does major mammals and birds. This flaw gave environmental and anti-development groups the ability to stop virtually any type of project they opposed by finding some obscure plant, animal or other species that "needed protection." This is the law that helped put "snail darter" in the environmental lexicon.

* Because the ESA treats populations of species the same as separate species, it can turn one area upside down when just across a political boundary, it is plentiful. Witness the gray wolf. An estimated 50,000 gray wolves live in Canada, yet just south of the border in Washington state it is "endangered." There is no shortage of gray wolves. Protecting them is both illogical and unneeded.

* The cost of saving a species, whether it's a pocket gopher or lichen, needs to be weighed against all of the other factors. In the case of the spotted owl, which is still listed as threatened, logging in many parts of the California and the Northwest was halted, helping to throw thousands of timber industry employees out of work. At the same time, the barred owl, which is close cousin to the spotted owl, was found to be thriving. It could be argued that the economic value of the timber industry is far greater than the "natural" value of an owl, whether it is spotted or barred.

* Government scientists have been buried by an avalanche of species proposed to be listed as endangered or threatened under the ESA. Because they must meet stringent deadlines for reviews, they serve as legal punching bags for environmental groups, which sue and settle the lawsuits, getting their lawyer bills paid by the federal government and allowing them to write the regulations for protecting species without going through a public process, as would normally be required.

In the meantime, taxpayers have been footing the bill -- amounting to billions of dollars -- to try to make a law work that is outdated and has done more to promote and fund environmental groups than the environment.

Congress, and the American people, should be interested in finding out how the law works now, how it can be improved to make it more effective and incorporate updated science.

Rep. Doc Hastings, chairman of the U.S. House Natural Resources Committee, has set up a working group to study the ESA. A review is long overdue. We urge him and others in Congress to give a serious, in-depth look at a law that history has shown to be in dire need of revision.

Such a revision should produce an updated law that is good for all species, including humans.